This post originally appeared on the blog Proud to be Primary.                             

The math tips and strategies you need for building number sense to 20 are right here. You will have everything you need to easily implement and bring a wealth of number sense activities, games, and centers into your classroom or home.

Building Number Sense to 20: Lessons & Activities for Kids

The activities, books, and resource suggestions (including a FREE one) cover a ton of number sense concepts and are perfect for Kindergarten and first grade. Plus, find valuable number sense materials and manipulative suggestions, as well as freebies you can access today! Warning: It’s LONG but filled with so much you won’t want to miss anything!

Why is Building a Number Sense Important?

Children need opportunities to learn and experience numbers. Learning to count, identify numbers, and understand quantity are a few of the important concepts. Repeated experiences build understanding and fluency with numbers. These experiences help students expand understanding and learn new concepts. A strong number sense is vital for future understanding of more complex math topics.

The activities below are ones that have been used successfully. Use them as they are described or adapt them for your own needs. Be flexible. Have conversations about numbers and encourage questions. When there is an opportunity to order, count, match, or describe with a child, go for it! They benefit from seeing numbers in natural, fluid ways.

Make time for fun and engaging number activities daily and watch fluency develop.

Number Sense Concepts & Activities

Build Number Sense Through Counting

It is very important to count with children every day. Repeated oral counting helps them hear what numbers sound like and to learn their order. Using math manipulatives, like counting chips, can help build a connection to oral counting and counting objects. This one-to-one counting is an important skill that needs to be practiced often.


  • Count out loud as a class starting at 1 and building to higher and higher numbers.
  • Sit with a partner or in a circle and take turns counting by 1’s.
  • As counting develops, teach number patterns and counting by 2’s, 5’s, and 10’s.
  • Use a number chart to visually see what numbers look like. Point to each number as it is said.
  • Encourage kids to practice one-to-one counting with small objects. Have small groups of objects set up in a center for them to count.
  • Provide number cards (like those seen below) for kids to represent with counting chips.

activities for building number sense to 20

Build Number Sense by Matching Numbers to Quantities

Provide materials for kids to count and connect with objects and numbers. This encourages children to see that numbers are more than words. Teach children that numbers have many representations, such as dots, fingers, counters, numerals, objects, ten frames, etc.


  • Match two different types of objects together, such as 5 counting bears and a domino that shows 5 dots.
  • Use links to create a number chain for a number.
  • Work up to showing quantity with more than 2 types of objects (as seen in the photo).
  • Have many different items available for activities, such as dice, dominoes, number magnets, bears, counting chips, cubes, and number cards.

activities for building number sense to 20

  • Match number cards from a card deck or game of Uno with dots on dominoes. Find every number combination on the dominoes.

matching number cards with dominoes for building number sense to 20

  • Complete number puzzles that have a different number representation on each piece. They help kids see that numbers can be modeled in many ways. These number puzzles to 20 are available as a FREE download further on.

FREE number representation posters - building number sense to 20

  • Encourage one-to-one counting with clip cards. Kids count groups of objects and clip the numeral that matches to the correct quantity.

clip card numbers for building number sense to 20

  • Ten frames are great for organizing numbers so that they can be easily counted. Matching numeral cards with ten frame representations is simple, yet effective at connecting quantity with numbers.

matching numbers with ten frames for building number sense to 20

Build Number Sense with Number of the Day

When kids see numbers in many ways at once repeatedly, their number sense develops. Pick a number of the day starting at 1 and dissect it during your math block.


  • Learn about a specific number for each day that you have been at school. Teach and dissect that number during calendar time. Represent that number on a number line, count to that number, show that number with straws or cubes, etc.
  • Use a number of the day poster or anchor chart to break numbers down. Create your own number of the day poster with the FREE poster templates.
  • Encourage kids to participate and show their understanding on paper or mini white boards. Ask a question, such as “How do we show 5 with tally marks?” and allow them time to try on their own. This makes a great fluency building warm-up to math lessons.
  • Read more tips on starting a number of the day routine in your classroom.

number of the day poster for building number sense to 20

Build Number Sense by Ordering Numbers

Provide opportunities for kids to put numbers in order. While they put numbers or objects with numbers on them into the correct order, they are counting and building number sense.


  • Provide opportunities with using a number line and number chart that puts numbers in order for us.
  • Give sets of numbers to order correctly by finding them on the number line.
  • Cover different numbers on a number chart with sticky notes and ask kids for the missing numbers.
  • Build Lego stacks by putting the pieces together in an order written on the blocks.

lego stacks to order numbers - building number sense to 20 lego stacks to order numbers for building number sense to 20

  • Work together with a partner to order number cards from 0 to 20. Create a number caterpillar like the one seen below.

ordering numbers caterpillar for building number sense to 20

  • Number puzzles are a fun way to order numbers. Put the strips in the right order to reveal a picture.

number puzzles for ordering numbers - building number sense to 20

  • Puzzles are simple and easy to create. Take an old puzzle and write numbers on the back of each piece.
  • Grab a piece of paper and write numbers in rows. Cut out pieces randomly and trade with a partner. Put the puzzle back together again for practice.

create a number puzzle to 20 for building number sense to 20

create a number puzzle to 20 for building number sense to 20

  • Complete a number order maze starting at 0. This activity can be reused when put into a pocket protector.

order numbers with this maze worksheet - building number sense to 20

Build Number Sense with Place Value Activities

Teaching kids about place value should begin with teaching them to see ten in many ways. Move on to illustrating numbers with base ten blocks.


  • Practice making groups of ten things. Group straws, beans, counters, or any small objects.
  • Teach counting by 10’s to count groups. Extend to teaching groups first and then singles.
  • Make groups of ten to get to the 100th day.
  • Show and examine a tens block and ones block. Discuss that a tens block has ten ones put together.
  • Use base ten blocks to represent numbers. Do plenty of examples where kids must use and count blocks. Use a chart to help count the blocks.
  • Say “Show (or draw) me 14 with place value blocks!”
  • Represent the number of tens and ones on place value mats (seen below). Ask questions like “How many ones are there?” or “How many groups of ten?”. Make sure they understand what each number within the number stands for (i.e., the 1 in 18 is a ten and not a one).

numbers represented with base ten blocks on place value mats - building number sense to 20

  • Represent a number in different ways: expanded form, standard form, word form, numeral, etc. Worksheets like the one below can help build this connection.

place value worksheets for building number sense to 20

Reading and Writing Numerals

Kids are constantly surrounded by numbers in their environment. They quickly learn to recognize the individual numerals 0 to 9 through different experiences. Continue to encourage this familiarity by having numbers on the wall. Posters, number lines, and calendars are helpful tools.


  • Build numbers with playdough in a math center. Even something simple as this playdough numbers activity here.
  • Print numbers from 0 to 9 daily in different ways – in booklets, on whiteboards during math lessons, etc.
  • Draw numbers on paper and give students do-a-dot markers or bingo dabbers to dot numbers.

dot numbers to practice formation and building number sense to 20

  • Use a Boogie Board (seen below) or whiteboard to quickly practice numbers over and over.

boogie board for tracing numbers and building number sense to 20

  • Trace numbers frequently and repeatedly to build coordination and correct form. The mini-book below encourages this, as well as locating numbers.

numbers 1 to 20 practice sheets for building number sense to 20

  • Encourage the correct formation of numbers by teaching it explicitly. The posters (seen below) are helpful tools to use and post on the wall.
  • Catchy number poems help students visualize and remember number formation. Use your whole body to make actions or draw in the air.

number formation poems for building number sense to 20

Reading and Writing Number Words

Teach kids how to read number words as they learn to read. Teach each number word one at a time and how to spell them phonetically (when applicable).


  • Have number posters with both the numeral and number word on it.
  • Include number words on spelling lists so that kids learn to read and spell number words.
  • Use a number of the day routine to teach and focus on one word each day.
  • Match numbers word cards with numeral cards (seen below).
  • Play memory with a partner with number word and numeral cards. Look for pairs (twelve and 12).

match number words and numeral cards for building number sense to 20

  • Build recognizing and speed with mental math flash cards cards. Flash cards to kids and they race to call out what they see (tally, numerals, number words, etc.).

mental math flash cards for building number sense to 20

Build Number Sense by Counting On and Back

Teach the strategy of counting on and back from a number to prepare kids for addition and subtraction.


  • Give students a number and a group of small objects to count on. Ask “How many more do I have?” given 7 to start and a group of 9 counters to count on with.
  • Play games with small objects and decks of cards where counting on is needed.
  • Play a group counting game called ‘Around the World’. Say a number and each person counts on and says the next number as you go around the circle.
  • Use small objects to count on or back from a number given (cubes, counters, dice, etc.).
  • Put numbers in backwards order. Take the ordering activities seem above and reverse them.

Build Number Sense through Estimating

Provide lots of opportunities for kids to guess how many things they see in their day to day lives. Ask prompting questions to encourage this thinking. Make sure kids know that they are estimating and that these are just guesses. Stress that estimates do not need to be exact but that they should be thoughtful. With more practice, estimations should become closer to the actual number of objects.


  • Fill clear or open containers with different sized objects for kids to guess. Keep them simple and work up in difficulty and size of objects. Smaller objects and bigger containers are usually harder.
  • Create an Estimation Station” where containers are set up with objects inside. Kids can take a close look and make estimates.

create an estimation station - building number sense to 20

  • As a whole group activity, grab a pile of objects to show quickly. Cover them and have kids make guesses.
  • Play ‘Show & Hide’ with a partner. Use a cup and put some small counting bears inside. Quickly show a partner and them hide them. They make an estimate and then you count together to check.

Here is the ultimate spot for teachers to find math tips and strategies for building number sense to 20 in Kindergarten and first grade. An extensive list of number sense activities and resources are included: books, materials, math manipulatives, and FREE activities you can access today!

Build Number Sense by Comparing Numbers

As familiarity with numbers grow, so does an ability to compare numbers with each other. Provide opportunities to compare numbers daily. Ask questions about which number is bigger, smaller, or the same.


  • Use a chart or number line to compare numbers.
  • Use small objects to make comparing easier. Say “Show 11 and 15 with cubes”. Ask “Which number is smaller?”.
  • Teach the symbols < > and = and what they each mean. Use the alligator strategy (The alligator likes to eat the bigger number) to remember the signs and what they mean.
  • Create number towers. Kids use cubes to form towers to represent numbers. Compare 2 towers to see which is the tallest and therefore the bigger number. The alligator eats the bigger tower.comparing numbers with number towers - building number sense to 20
  • Compare numbers with math tools and indicate the correct symbol on clip cards (seen below). As kids become fluent, they should recognize the correct symbol without support.

comparing numbers clip cards - building number sense to 20

Number Sense Resources

The activities seen in this post can be found in the following resources found on Teachers Pay Teachers.

Numbers to 5 for Kindergarten

Numbers to 10 for Kindergarten

Numbers 11-20 for Kindergarten

Mindful Math Kindergarten Curriculum

Numbers to 10 for First Grade

Numbers to 20 for First Grade

Mindful Math First Grade Curriculum

Free Number Sense Puzzles to 20

Grab 20 FREE number puzzles with different representations on each piece by clicking the image below.

Number Sense Books

Math tips and strategies for building number sense to 20 in Kindergarten and first grade. An extensive list of number sense activities and resources are included: books, materials, math manipulatives, and FREE activities! #mathforkids #firstgrade #kindergartenmath #firstgrademath #kindergarten #numbersense #numberactivities #mathactivitiesforkids
I Spy Numbers by Jean Marzollo
1,2,3 Peas by Keith Baker
Chicka Chicka 1,2,3 by Bill Martin Jr.
Splash! by Ann Jonas (counting)
The Very Hungry Caterpillar by Eric Carle (counting)
How Do Dinosaurs Count to 10? by Jane Yolen
Number Everywhere by Elliot Kaufman
10 Black Dots by Donald Crews
How Many Bugs in a Box? by David Carter
How Many Snails? by Paul Giganti, Jr.
Ten Sly Piranhas by William Wise
None the Number by Oliver Jeffers
Zero the Hero by Joan Holub
More or Less by Stuart Murphy
Tally O’Mally by Stuart Murphy
Place Value by David Adler
What’s the Place Value by Shirley Duke
Quack and Count by Keith Baker
Betcha! by Stuart J. Murphy

Learn More about Teaching Number Sense

Building Number Sense - free email series

Building Number Sense free email series

number of the day activities

Number of the Day Activities

5 tips for building math fluency

5 Tips for Building Math Fluency

number sense activities post PINS (2)


Elyse Rycroft has 10 years experience working as a primary (K-3) teacher in British Columbia, Canada. She is the author of the teaching blog, Proud to be Primary, where she shares teaching tips, management strategies, and lesson ideas to thousands of teachers daily! Specializing in Math, Art, and Poetry, she is dedicated to creating curriculum resources that are engaging, differentiated, and comprehensive. You can find her resources in her TpT store, Proud to be Primary. Connect with her on Facebook and Instagram.